Piotr Achinger

EPDI postdoc at IHES

Office 0N1

About me

My name is Piotr Achinger, I am currently (2016-2017) spending the second year of my EPDI postdoc at the IHES in Bures-sur-Yvette.

I got my PhD in Mathematics in 2015 from University of California, Berkeley; it was my pleasure to work under the guidance of Arthur Ogus. The first three years of my PhD were supported by an International Fulbright Science and Technology Fellowship. I spent the first year (2015-2016) of my EPDI postdoc at the Banach Center at IM PAN in my home city of Warsaw.

My thesis K(pi, 1) Spaces in Algebraic Geometry


  • algebraic geometry in characteristic p
  • Frobenius splittings
  • etale fundamental group
  • deformation theory
  • Calabi-Yau varieties
  • logarithmic geometry


  1. Frobenius Push-Forwards on Quadrics, Communications in Algebra 40:8 (2012) (arXiv)
  2. (with Nicolas Perrin) Spherical multiple flags, in Schubert Calculus – Osaka 2012, Advanced Studies of Pure Mathematics vol. 71, 2017 (arXiv)
  3. A characterization of toric varieties in positive characteristic, International Mathematics Research Notices 16 (2015) (arXiv)
  4. K(pi, 1)-neighborhoods and comparison theorems, Compositio Mathematica 151 (2015) (arXiv)
  5. (with Nathan Ilten and Hendrik Süß) F-Split and F-Regular Varieties with a Diagonalizable Group Action, to appear in Journal of Algebraic Geometry (arXiv)
  6. (with Maciej Zdanowicz) Some elementary examples of non-liftable varieties, to appear in Proceedings of the AMS (arXiv)
  7. Wild ramification and K(pi, 1) spaces, Inventiones Mathematicae (online first, Open Access at SpringerLink) (arXiv)


  1. (with Jakub Witaszek and Maciej Zdanowicz) Liftability of the Frobenius morphism and images of toric varieties (arXiv) (video of my talk at BIRS in Oaxaca) (notes from that talk)

Other projects


Spring 2016

Junior Algebraic Geometry Seminar (with Maciej Zdanowicz)